The complex & diverse terrain of Halong encompassing 3 regions: the mountainous area; the coastal area and the bay & island area, strongly influences Halong Bay weather and climate.

Table Contents
weather in halong
Source: Taylor Simpson

I - An overview about Halong Bay weather & climate 

Located in the hot & humid tropical climate zone, Halong Bay's weather is affected by 2 types of monsoon: the northeast wind in winter and southwest wind in summer. There are 4 seasons in Halong Bay, in which winter and summer are the main seasons, spring and autumn are the transitional seasons lasting for a short time. 

- Winter (dry & cold): from November to the end of February, the temperature is about 15 - 20°C

- Spring (warm): from March to the end of April, the temperature is about 23°C


halong bay weather forecast

How is the weather in Halong Bay Vietnam? Source: Kenh14

- Summer (hot & wet): from May to the end of August, the average temperature is 28.6°C, the hottest month is August with a peak of the temperature of 38.5°C. 

- Autumn (cool): from early September to the end of October, the temperature is about 24.6 - 27.3°C

The average annual temperature in Halong bay is about 24°C, the humidity is 84% and the rainfall is about 1832mm reaching its peak in July & September. Located in an enclosed sea, this area is rarely affected by major storms. The strongest winds in the storms usually reach level 9 and level 10.

II - Halong Bay weather by month

1 - In winter from November to March

Halong Bay in winter is dry & cold with the temperature varying from 8°CC to 20°C. There is little sun and fog sometimes appears. In winter, sea activities such as cruising, kayaking, swimming are more or less hindered and you should check the weather forecast regularly.

Weather in Halong Bay in October

It is dry with a temperature of 24°C. October is also the beginning of the peak season for international tourists to Halong Bay. If you want to travel here during this time, you should make a reservation in advance

In December

It is dry and not too cold in December. The average temperature is about 17°C and decreases at night. This is also the peak of the dry season with about 19mm of rainfall. There are no more sudden rains and the sky is clearer suitable for visiting the bay

Top amazing caves in Halong bay

Halong Bay weather January

In January, there is much rain and the temperature is lower compared to December. 


Fog begins to appear over the bay, The temperature is 16°C and rainfall is 22mm


The weather in March gradually warms up with the temperature about 19°C. The often-occur fog creates a fanciful and romantic scene. On days without fog, the sky is usually clear, with a lot of sunshine. Mountain climbing is an interesting activity that you should not miss when coming to Ha Long in March.

2 - Halong Bay weather in spring - April 

halong bay temperature

Carnival Ha Long - Source: Internet

April is the transactional time between winter and summer with the temperature being 23°C and rainfall being 90mm. Halong Bay weather in April is so pleasant, facilitating sea tourism, leisure tourism,... The end of April in time for Carnaval Halong - a unique festival to introduce the breathtaking landscape and cultural features in Halong.

The best time to visit Halong bay

2 - Weather in Halong Bay in summer - from May to September 

Halong Bay in summer is extremely hot with high temperatures (up to 37°C in July & August) and it’s wet due to the heavy rains. The sunshine and no-cloudy days in summer are the best time for outdoor activities such as kayaking, swimming, sunbathing. There is heavy rain and major storms in summer which affects cruise tours. 

Coming to Halong Bay in summer,  you need to pay more attention to the Halong Bay weather forecast to limit visiting on cloudy & rainy days caused by storms and tropical depressions. Also, you should bring sunscreen, long sleeve shirts with bright colors, and wide-brimmed hats to avoid the harsh sunlight at noon. 


May is the end of the international tourist season in Halong Bay. The weather in May is a bit hot with an average temperature of 27°C.


It welcomes more pouring rains and the temperature in June is getting higher up to 30°C. The Storm season starts in June, so you should be careful and regularly check the weather forecast. 

Halong Bay weather in July and August

The temperature and rainfall in Halong Bay reach peaks. It is about 38°C and the monthly rainfall is 350mm. The bad & unstable weather can let you down with outdoor activities. 


Compared to a couple of months previously, the temperature in September decreased slightly, fluctuating from 24°C to 33°C.

Top things to do in Halong bay

4 - Weather in Halong Bay in autumn - October  

halong typhoon

Source: John Mayer

Temperature and rainfall continue to decrease dramatically compared to September. Storms are likely to appear but for less often than in summer. 

Best beaches for kayaking in Halong bay

In general, Halong Bay weather is quite temperate, which is considered as a key pull factor attracting more tourists visiting here all year round. To limit the negative impact of bad weather, the best time to visit Halong Bay is from March to May and from September to November.

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